Device for expanding liquefied gas with separate vaporising element

ABSTRACT

Arrangement for expanding liquefied gas. The arrangement includes a vaporizing element having a heat exchanger. The heat exchanger has an impermeable enclosure containing a heating fluid and a vaporizing tube made of a heat conducting material through which the liquefied gas passes. The vaporizing tube includes an intake connected to a supply reservoir and an outlet supplying vaporized gas. An element is provided for regulating a flow rate and a pressure of vaporized gas. A tube connects the outlet of the vaporizing tube to the element for regulating a flow rate and a pressure of vaporized gas. The element for regulating a flow rate and a pressure of vaporized gas is connected to an engine. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The instant application is a U.S. National Stage Application ofInternational Application No. PCT/FR00/03609 filed on Dec. 20, 2000 andpublished as International Publication WO 02/50416 on Jun. 27, 2002.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention is directed to a device for expandingliquefied gas with a separate vaporizing element.

[0004] The invention provides for an arrangement which allows the supplyof liquefied petroleum gas (L.P.G.) for use in ignition engines normallyreceiving a liquid fuel.

[0005] It is suitable for all types of internal combustion engines, andit is adapted in particular to boat engines.

[0006] 2. Description of the Prior Art

[0007] Liquefied petroleum gas is used more and more as a source ofenergy for motor vehicles. Indeed, this fuel has very interestingadvantages, chief among which a very low pollution must be listed, andan advantageous charge rate used by numerous countries, allowing asubstantial decrease in the kilometric cost.

[0008] The use of liquefied gas to operate an engine which was initiallydesigned to receive a liquid fuel requires using a specific deviceensuring the vaporization of the gas under a predetermined pressure andflow rate.

[0009] This device is usually in the form of a housing, generally madeof a light metal cast iron, such as aluminum, and comprising a doubleenclosure formed of a gas vaporizing chamber and a thermal chamber inwhich a hot liquid circulates, which is most often constituted by theengine cooling water drawn due to a shunt made on the circuit connectingthe latter to the radiator, or to the evacuation pipeline in the case ofboat engines cooled with sea water. The two chambers have a common wallarranged to allow for the transmission of calories.

[0010] The vaporizing chamber also acts as a pressure regulator and, tothis end, comprises a valve that is generally activated by an internalmembrane.

[0011] The design of this system causes a certain number of drawbacks.

[0012] Given that the transfer of heat occurs through the wall that iscommon to the two chambers, and that the other walls of the vaporizingchamber communicate with the outside, substantial losses of caloriesoccur, and in order to obtain a right vaporization of the liquefied gas,manufacturers have to provide separation walls in the form of alabyrinth in order to increase the common surface, which obviouslygenerates high manufacturing costs. Despite these arrangements, it isnecessary in certain cases to provide an additional heating means, forexample, an electrical resistance as the one described in the Patent No.FR 2 759 419, or an outer impermeable enclosure provided with a heatsupply element and connected to the thermal chamber of the vaporizinghousing by a double canalization in a closed circuit, as one in whichcirculates a fluid ensuring the transfer of the calories produced in theheated enclosure toward the vaporizer, this device being the object ofthe Patent Application No. FR 98 08 110.

[0013] Furthermore, the existing apparatuses do not allow supplying highpowered engines and, in this case, one must provide several steampressure regulators for a single engine.

SUMMARY OF THE INVENTION

[0014] The device according to the present invention aims to overcomethese drawbacks. Indeed, it can be easily adapted to engines of alltypes and sizes, and it allows for a substantial decrease in themanufacturing costs due to the simplicity of its design, while ensuringan excellent heat exchange between the gas to be vaporized and theheating fluid.

[0015] It is formed of two independent parts linked by a single tube.The two parts are an element for regulating the flow rate and thepressure of the vaporized gas, connected to the engine, and a vaporizingelement utilizing a heat exchanger constituted of a tube made of a heatconducting material in which the gas passes, liquid at the intakeconnected to the supply reservoir and gaseous at the outlet. The tube isimmerged in the heating liquid that is itself contained in an enclosuremade preferably of an insulating material.

[0016] The invention provides for an arrangement for expanding liquefiedgas, wherein the device comprises a vaporizing element comprising a heatexchanger. The heat exchanger comprises an impermeable enclosurecontaining a heating fluid and a vaporizing tube made of a heatconducting material through which the liquefied gas passes. Thevaporizing tube comprises an intake connected to a supply reservoir andan outlet supplying vaporized gas. An element is provided for regulatinga flow rate and a pressure of vaporized gas. A tube connects the outletof the vaporizing tube to the element for regulating a flow rate and apressure of vaporized gas. The element for regulating a flow rate and apressure of vaporized gas is connected to an engine.

[0017] The tube may be a single tube. The tube may be immerged in theheating fluid contained in an impermeable enclosure. The liquefied gasmay comprise liquefied petroleum gas (LPG). The engine may comprise aninternal combustion engine. The engine may comprise a boat engine. Theelement for regulating a flow rate and a pressure of vaporized gas maylack a thermal chamber. The element for regulating a flow rate and apressure of vaporized gas may comprise a housing having a bottom, acover and an intake, a flexible membrane arranged between the bottom andthe cover, and a valve coupled to the intake. The valve may comprise adecelerating valve.

[0018] The impermeable enclosure may be made of an insulating material.The heat exchanger may comprise a tubular heat exchanger and thevaporizing tube may comprise a coil of substantial length arranged in afolded manner.

[0019] The impermeable enclosure may comprise a reinforced rubber tubehaving two ends, and angled connectors arranged on each of the two ends.The vaporizing tube may pass through each of the angled connectors.

[0020] The device may further comprise a low-voltage electric heatingcord wound about the vaporizing tube.

[0021] The vaporizing element may further comprise a valve for stoppingthe liquefied gas. The valve may be arranged at the intake. The valvemay be controlled by a pressure sensor.

[0022] The device may further comprise a system for controlling a flowrate of the heating fluid.

[0023] The vaporizing element may comprise a system for controlling aflow rate of the heating fluid. The system may be controlled by atemperature sensor.

[0024] The invention also provides for a method of supplying vaporizedliquefied petroleum gas (LPG) to an engine using the arrangementdescribed above, wherein the method comprises moving the heating fluidthough the heat exchanger, moving the LPG from the supply reservoir tothe intake and through the vaporizing tube, creating the vaporized LPGwithin the vaporizing tube, moving the vaporized LPG through the tubeconnecting the outlet of the vaporizing tube to the element forregulating a flow rate and a pressure of vaporized gas, regulating theflow rate and the pressure of the vaporized LPG, and delivering thevaporized LPG to the engine.

[0025] The invention also provides for a method of supplying vaporizedliquefied petroleum gas (LPG) to a boat engine using the arrangementdescribed above, wherein the method comprises moving the heating fluidthough the heat exchanger, moving the LPG from the supply reservoir tothe intake and through the vaporizing tube, creating the vaporized LPGwithin the vaporizing tube, moving the vaporized LPG through the tubeconnecting the outlet of the vaporizing tube to the element forregulating a flow rate and a pressure of vaporized gas, regulating theflow rate and the pressure of the vaporized LPG, and delivering theregulated vaporized LPG to the engine.

[0026] The invention also provides for a system for delivering vaporizedLPG to an engine, wherein the system comprises a heat exchangercomprising an impermeable enclosure containing a heating fluid and avaporizing tube made of a heat conducting material through which the LPGpasses, wherein the vaporizing tube comprises an intake connected to asupply reservoir and an outlet supplying vaporized LPG, a regulatingdevice for regulating a flow rate and a pressure of vaporized LPG, and atube connecting the outlet of the vaporizing tube to the regulatingdevice, wherein the regulating device is connected to the engine.

[0027] The invention also provides for a method of supplying vaporizedliquefied petroleum gas (LPG) to an engine using the system describedabove wherein the method comprises moving the heating fluid though theheat exchanger, moving the LPG from the supply reservoir to the intakeand through the vaporizing tube, creating the vaporized LPG within thevaporizing tube, moving the vaporized LPG through the tube connectingthe outlet of the vaporizing tube to the regulating device, regulatingthe flow rate and the pressure of the vaporized LPG, and delivering thevaporized LPG to the engine.

[0028] The invention also provides for a method of supplying vaporizedliquefied petroleum gas (LPG) to a boat engine using the systemdescribed above wherein the method comprises moving the heating fluidthough the heat exchanger, moving the LPG from the supply reservoir tothe intake and through the vaporizing tube, creating the vaporized LPGwithin the vaporizing tube, moving the vaporized LPG through the tubeconnecting the outlet of the vaporizing tube to the regulating device,regulating the flow rate and the pressure of the vaporized LPG, anddelivering the vaporized LPG to the boat engine.

[0029] The invention also provides for a system for supplying vaporizedLPG to a boat engine, wherein the system comprises a heat exchangercomprising an impermeable enclosure containing a heating fluid and avaporizing tube made of a heat conducting material through which the LPGpasses. The vaporizing tube comprises an intake connected to a supplyreservoir and an outlet supplying vaporized LPG. A regulating device isprovided for regulating a flow rate and a pressure of vaporized LPG. Theregulating device comprises a housing which contains a flexible membraneand a valve. A tube connects the outlet of the vaporizing tube to theregulating device. The regulating device is connected to the boatengine.

[0030] The invention also provides for a method of supplying vaporizedliquefied petroleum gas (LPG) to a boat engine using the systemdescribed above wherein the method comprises moving the heating fluidthough the heat exchanger, moving the LPG from the supply reservoir tothe intake and through the vaporizing tube, heating the LPG within thevaporizing tube with the heating fluid such that the vaporized LPG iscreated within the vaporizing tube, moving the vaporized LPG through thetube connecting the outlet of the vaporizing tube to the regulatingdevice, regulating the flow rate and the pressure of the vaporized LPG,and supplying the vaporized LPG to the boat engine.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In the attached schematic drawings, given by way of non-limitingexample embodiments of the invention:

[0032]FIG. 1 shows the vaporizing element and regulating elementassembly;

[0033]FIGS. 2 and 3 show, in cross-section, on a different scale, thevaporizing element and regulating element of FIG. 1, respectively; and

[0034]FIGS. 4 and 5 show, also in cross-section, alternative embodimentsof the vaporizing element.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0035] The device, FIGS. 1-5, is constituted of a vaporizing element 1and of an element 2 for regulating the pressure and the flow rate. Thesetwo elements are separate and connected by a tube 3 that can be aflexible tube.

[0036] The regulating element 2 is consistent with devices usuallyintegrated in common steam-pressure regulators, but it is not providedwith a thermal chamber. It essentially comprises a flexible membrane 4engaged between the bottom 5 and the cover 6 of a housing and acting ona valve 7 arranged on the intake 8 of the gas originating from thevaporizing element 1. The regulating element 2 can be equipped withaccessories (not shown) mounted on the known devices, such as adecelerating valve, or multiple chambers with different pressures.

[0037] The vaporizing element 1 utilizes a heat exchanger constituted ofan impermeable enclosure 9 advantageously made of an insulating materialand in which the heating fluid 10 circulates. A tube 11, preferably madeof brass or of bronze, is immerged in this liquid and is connected tothe reservoir of liquefied gas on one side and to the regulating element2 on the other side. It is in this tube that the gas is vaporized, dueto the calories supplied by the heating fluid 10.

[0038] The impermeable enclosure 9 and the vaporizing tube 11 can be ofany form and arrangement.

[0039] In particular, according to a first alternative embodiment shownin FIG. 4, the vaporizing element 1 is constituted of a tubular heatexchanger of a known type with a vaporizing tube 11 folded over severaltimes in order to form a coil of substantial length.

[0040] According to a second alternative embodiment shown in FIG. 5, theimpermeable enclosure is constituted of a reinforced rubber pipe 12 ofthe DURITE® type through which the vaporizing tube 11 passes, and whichis closed at its two ends by angled connections 13 traversed by thevaporizing tube. This arrangement allows easily adapting the features(length, diameter, curvature) of the vaporizing element to all casesthat can be presented.

[0041] The device can possibly be equipped with a low-voltage electricheating cord wound about the vaporizing tube 11.

[0042] The assembly is advantageously completed by safety devicescommonly used in these types of embodiments, such as a valve forstopping the liquid gas at the intake of the vaporizing element 1, or asystem for regulating the flow rate of the heating fluid 10, thesedevices being controlled by pressure or temperature sensors.

[0043] Due to its simplicity, its ease of mounting and its lowproduction cost, the device that has just been described lends itselfparticularly well to making systems for steam-pressure regulators ofliquefied petroleum gas that can be adapted indifferently to all typesof engines.

[0044] Consequently, the invention is not limited to the one form ofembodiment of this device for vaporizing liquefied gas describedhereinabove by way of example; instead, it encompasses all of thevariants of embodiment and application that conform to the sameprinciples.

[0045] The positioning of the various constitutive elements gives theinvention a maximum of useful effects that until now had not beenobtained by similar devices.

1-9. (canceled).
 10. An arrangement for expanding liquefied gas, thearrangement comprising: a vaporizing element comprising a heatexchanger; the heat exchanger comprising an impermeable enclosurecontaining a heating fluid and a vaporizing tube made of a heatconducting material through which the liquefied gas passes, wherein thevaporizing tube comprises an intake connected to a supply reservoir andan outlet supplying vaporized gas; an element for regulating a flow rateand a pressure of vaporized gas; and a tube connecting the vaporizingtube to the element for regulating a flow rate and a pressure ofvaporized gas, wherein the element for regulating a flow rate and apressure of vaporized gas is connected to an engine.
 11. The arrangementof claim 10, wherein the tube is a single tube.
 12. The arrangement ofclaim 10, wherein the tube is immerged in the heating fluid contained inan impermeable enclosure.
 13. The arrangement of claim 10, wherein theliquefied gas comprises liquefied petroleum gas (LPG).
 14. Thearrangement of claim 10, wherein the engine comprises an internalcombustion engine.
 15. The arrangement of claim 10, wherein the enginecomprises a boat engine.
 16. The arrangement of claim 10, wherein theelement for regulating a flow rate and a pressure of vaporized gas lacksa thermal chamber.
 17. The arrangement of claim 10, wherein the elementfor regulating a flow rate and a pressure of vaporized gas comprises ahousing having a bottom, a cover and an intake, a flexible membranearranged between the bottom and the cover, and a valve coupled to theintake.
 18. The arrangement of claim 17, wherein the valve comprises adecelerating valve.
 19. The arrangement of claim 10, wherein theimpermeable enclosure is made of an insulating material.
 20. Thearrangement of claim 10, wherein the heat exchanger comprises a tubularheat exchanger and wherein the vaporizing tube comprises a coil ofsubstantial length arranged in a folded manner.
 21. The arrangement ofclaim 10, wherein the impermeable enclosure comprises a reinforcedrubber tube having two ends, and angled connectors arranged on each ofthe two ends.
 22. The arrangement of claim 21, wherein the vaporizingtube passes through each of the angled connectors.
 23. The arrangementof claim 10, further comprising a low-voltage electric heating cordwound about the vaporizing tube.
 24. The arrangement of claim 10,wherein the vaporizing element further comprises a valve for stoppingthe liquefied gas.
 25. The arrangement of claim 24, wherein the valve isarranged at the intake.
 26. The arrangement of claim 24, wherein thevalve is controlled by a pressure sensor.
 27. The arrangement of claim10, further comprising a system for controlling a flow rate of theheating fluid.
 28. The arrangement of claim 10, wherein the vaporizingelement comprises a system for controlling a flow rate of the heatingfluid.
 29. The arrangement of claim 28, wherein the system is controlledby a temperature sensor.
 30. A method of supplying vaporized liquefiedpetroleum gas (LPG) to an engine using the arrangement of claim 10, themethod comprising: moving the heating fluid though the heat exchanger;moving the LPG from the supply reservoir to the intake and through thevaporizing tube; creating the vaporized LPG within the vaporizing tube;moving the vaporized LPG through the tube connecting the outlet of thevaporizing tube to the element for regulating a flow rate and a pressureof vaporized gas; regulating the flow rate and the pressure of thevaporized LPG; and delivering the vaporized LPG to the engine.
 31. Amethod of supplying vaporized liquefied petroleum gas (LPG) to a boatengine using the arrangement of claim 10, the method comprising: movingthe heating fluid though the heat exchanger; moving the LPG from thesupply reservoir to the intake and through the vaporizing tube; creatingthe vaporized LPG within the vaporizing tube; moving the vaporized LPGthrough the tube connecting the outlet of the vaporizing tube to theelement for regulating a flow rate and a pressure of vaporized gas;regulating the flow rate and the pressure of the vaporized LPG; anddelivering the regulated vaporized LPG to the engine.
 32. A system fordelivering vaporized LPG to an engine, the system comprising: a heatexchanger comprising an impermeable enclosure containing a heating fluidand a vaporizing tube made of a heat conducting material through whichthe LPG passes, wherein the vaporizing tube comprises an intakeconnected to a supply reservoir and an outlet supplying vaporized LPG; aregulating device for regulating a flow rate and a pressure of vaporizedLPG; and a tube connecting the outlet of the vaporizing tube to theregulating device, wherein the regulating device is connected to theengine.
 33. A method of supplying vaporized liquefied petroleum gas(LPG) to an engine using the system of claim 32, the method comprising:moving the heating fluid though the heat exchanger; moving the LPG fromthe supply reservoir to the intake and through the vaporizing tube;creating the vaporized LPG within the vaporizing tube; moving thevaporized LPG through the tube connecting the outlet of the vaporizingtube to the regulating device; regulating the flow rate and the pressureof the vaporized LPG; and delivering the vaporized LPG to the engine.34. A method of supplying vaporized liquefied petroleum gas (LPG) to aboat engine using the system of claim 32, the method comprising: movingthe heating fluid though the heat exchanger; moving the LPG from thesupply reservoir to the intake and through the vaporizing tube; creatingthe vaporized LPG within the vaporizing tube; moving the vaporized LPGthrough the tube connecting the outlet of the vaporizing tube to theregulating device; regulating the flow rate and the pressure of thevaporized LPG; and delivering the vaporized LPG to the boat engine. 35.A system for supplying vaporized LPG to a boat engine, the systemcomprising: a heat exchanger comprising an impermeable enclosurecontaining a heating fluid and a vaporizing tube made of a heatconducting material through which the LPG passes, wherein the vaporizingtube comprises an intake connected to a supply reservoir and an outletsupplying vaporized LPG; a regulating device for regulating a flow rateand a pressure of vaporized LPG; the regulating device comprising ahousing which contains a flexible membrane and a valve; and a tubeconnecting the outlet of the vaporizing tube to the regulating device,wherein the regulating device is connected to the boat engine.
 36. Amethod of supplying vaporized liquefied petroleum gas (LPG) to a boatengine using the system of claim 35, the method comprising: moving theheating fluid though the heat exchanger; moving the LPG from the supplyreservoir to the intake and through the vaporizing tube; heating the LPGwithin the vaporizing tube with the heating fluid such that thevaporized LPG is created within the vaporizing tube; moving thevaporized LPG through the tube connecting the outlet of the vaporizingtube to the regulating device; regulating the flow rate and the pressureof the vaporized LPG; and supplying the vaporized LPG to the boatengine.